The disclosed subject matter relates to a system and method for measuring temperature within a turbine system.
Certain power generation systems include a gas turbine engine configured to combust a mixture of fuel and compressed air to produce hot combustion gases. The combustion gases may flow through a turbine to generate power for a load, such as an electric generator. To enhance efficiency, certain power generation systems employ a heat recovery steam generator (HRSG) to capture energy from the hot combustion gases exhausted from the turbine. In general, HRSGs convey a fluid, such as water, through multiple conduits in a direction crosswise (e.g., substantially perpendicular) to the flow of exhaust gas. As the exhaust gas flows across the conduits, heat is transferred from the exhaust gas to the water, thereby producing steam. The steam is then directed through a steam turbine to generate rotational motion, thereby driving a load, such as an electric generator. The steam is exhausted to a condenser, which cools the steam to generate water for the HRSG. For example, the condenser conveys a fluid, such as water, through multiple conduits in a direction crosswise (e.g., substantially perpendicular) to the flow of steam. As the steam flows across the conduits, heat from the steam is transferred to the water, thereby condensing the steam into water.
As will be appreciated, temperature variations across the exhaust flow into the HRSG may decrease efficiency of the steam generation process. For example, if a portion of the exhaust flow is cooler than desired, water flow through certain conduits may not be sufficiently heated to produce steam. Conversely, if a portion of the exhaust flow is warmer than desired, certain conduits may experience excessive steam pressure. Such flow variations within the HRSG may decrease HRSG efficiency and/or result in premature wear of certain HRSG components. Similarly, temperature variations across the steam flow into the condenser may decrease efficiency of the steam turbine. For example, variations in the steam temperature distribution may induce density variations within the last stage of the steam turbine, thereby reducing turbine efficiency.